Control system for trolley switches



- E, A- LARSSON CONTROL SYSTEM FOR TROLLEY SWITCHES Filed June 7, 1947 3 Sheets-Sheet 1 I INVENTOR. ERNST A. LARSSON 13, 1949' E. A. LARsso N CONTROL SYSTEM FOR TROLLEY SWITCHES 3 Sheets-Sheet 2 Filed- June '7, 1947 IIIIIII/III l/Il/II/n 111/! [III/Ill,"III/III/IIIIl/IIIIA o o IIIIIIIII/IIII 7.

Zif u INVENTOR. ERNST A. LARS'SON E. A. LARSSON 2,490,909

CONTROL SYSTEM FOR TROLLEY SWITCHES Filed June 7,. 1947 s Sheets-Sheet a INVENTOR. ERNST A. LARssoN BY M Patented Dec. 13, 1949 UITED STATES OFFICE CQNTROL SYSTEM FOR TROLLEY SWITCHES Application June 7, 1947, Serial No. 753,212

24 Claims.

This invention relates to the operation of electrically operated vehicles and trolley frogs or switches for use in guiding current collectors mounted on the vehicle along the desired path of travel.

In trolley bus operation it is now practically standard practice to use two overhead trolley wires of opposite polarity. At turnout or switching points trolley frogs or switches are employed provided with means to guide the current collectors through the switches or frogs.

In trolley bus operation the vehicle is free to either follow along parallel to the wires either directly below same or to one side thereof or to move obliquely thereto at turnout points.

The trolley frogs being arranged to guide the current collectors through the frogs in the proper direction, it is necessary to provide means to actuate the guide means as required.

Therefore electrical means is now employed to effect and control the movements of the switch guide or tongue including the further use of contacts arranged to be engaged by the current collectors before the current collectors enter the switches or frogs to control the operation of the guide operating means.

Up to now it is the practice to make use of the ability of the vehicle operator to change the direction of travel of the vehicle relative to the trolley wires before the current collectors engage the contacts for controlling the operation of the electric operating means for the guides.

The method set forth above which has been in use up to date is disclosed in U. S. Patent 2,264,839 and a switch or frog adapted for the purpose is also disclosed therein.

The operation of the guides or tongues in the above described method depends upon the vehicle making the proper angling movement relative to the trolley wires at the right point of travel so as to engage the contacts in proper order and since experience shows that this is not always possible, the herein described invention permits the vehicle operator to adjust the current collectors relative to the contacts or to even make the entire adjustment independent of the angularity of the vehicle to the trolley wires as later more fully explained.

The invention herein disclosed provides means whereby the vehicle operator from within the vehicle may control the longitudinal spacing of the current collectors either independent of or in conjunction with the above described method and thereby assure proper operation of the frogs.

This invention will be better understood by ref- J erence to the following description taken in conjunction with the accompanying drawings, and particularly pointed out in the claims.

In the drawings:

Fig. 1 is a top plan of this invention as mounted on the roof or a vehicle, omitting however details of the trolley base.

Fig. 2 is an enlargement of one of the units shown in Fig. l, omitting as in Fig. 1 details of the trolley base.

Fig. 3 is a side view in partial section on the central longitudinal line 33 of Fig. 2 but shows in detail the side construction of the trolley base, not shown in Figs. 1 and 2.

Fig. 4 is a sectional view of a control valve used in the operation of this invention. 7

Fig. 5 is a partial section taken on the line 55 of Fig. 2, and Fig. 6 shows in partial section apparatus by which this invention may be controlled electrically by push buttons.

Fig. 7 is a schematic arrangement of two main and two branch conductors with trolley frogs at their intersections as used in present systems and in my improved system.

Fig. 8 shows schematically the angle which the vehicle and the current collectors take relative to the trolley Wires when approaching a switch to make a turn and when paralleling the trolley wires.

Fig. 9 shows a trolley pole with a current collector at its upper end in contact with a trolley wire.

Fig. 10 is a top plan view of a modified form of the herein disclosed invention as mounted on the roof of a vehicle, omitting details of the trolley base shown in Figs. 11 and 12.

Fig. 11 is a side View of the invention shown in Fig. 10.

Fig. 12 is a sectional view on the line I 2-42 of Fig. 10 except the trolley base is shown in detail.

In a preferred embodiment of this invention there is mounted on the roof of the vehicle I a pair of independent units 2 in duplicate. Each unit is mounted on members 3 preferably of Wood.

Each unit comprises a pair of grooved supports and guides 4 secured to the members 3. Supported by the members 4 in the grooves thereof is a sub-base 5 slidable longitudinally of and parallel to the longitudinal axis of the vehicle and adapted to have its movement in one direction limited by end means 6 as in Fig. 2.

Mounted on the sub-base 5 is a trolley base 1 shown more complete in Fig. 3 with interposed insulators 8 which are necessary as the trolley bases are oppositely charged electrically. The sub and trolley bases on vehicles now in extensive use are fixed as to longitudinal and transverse movement relative to the vehicle.

The base I as shown is well known and consists of a pedestal 9 with a turret l9 pivotally mounted upon the upright portion 8' thereof and a trolley pole support H pivotally mounted on the turret with a spring 52 connected to the turret and to the pole support tending to raise the support and pole 13. A full description of the trolley base i is found in U. S. Patent 1,773- 229 but not claimed herein in detail.

Mounted on the upper end of each trolley pole I3 is a current collector M which may be of the wheel or sliding shoe type and clearly shown and described in U. S. Patent 1,893,383.

Positioned rearwardly of the sub-base and secured to the members 3, is a spring pocket l5 in which is mounted one end of spring 16 with its other end engaging the sub-base 5 and through the medium of the spring retaining mountings ll thereon in its normal position against the stops 6.

In order to move the sub-base with the trolley base and current collectors longitudinally at will of the vehicle operator a pneumatic cylinder 18 and piston is are mounted on the members 3 and a rod 29 from the piston engages the subbase 5 whereby when fluid under pressure is admitted to the cylinder [8 the sub-base and mountings l1 thereon will be moved against the spring When the fluid pressure is released from the cylinder IS the spring l6 forces the sub-base and piston [9 forward to their normal positions.

Not infrequently the trolley pole and collectors are dewired while the vehicle is moving and they may become caught in the overhead construction with damage to the overhead, the trolley pole and the current collectors, but to avoid the :pull of the trolley pole operating the sub-base and mountings against spring 16 means to lock these parts in their normal position is provided consisting of a hook member 2| secured to the cylinder member l8 and a pivotally mounted hook member 22 mounted on a projection of the subbase and arranged to interlock with the member 2|.

The member 22 has a projection 23 against which the rod 2!] acts and when the rod 20 moves forward, the member 22 is released from the members 2| and the projection 23 compresses the spring 24 until the projection engages the spring cup 25 which is fixed to the sub-base 5 and then the sub-base 5 moves back against the spring 16.

In order to operate the units independently the cylinders l8 are connected to a source 26 of fluid pressure as shown in Fig. 1 with valves 21 and 21' to control each unit. The valves are connected to the respective cylinders l8 by pipes 28 and to the compressor 28 by pipes 29.

When the valves 21 and 2'! are set as in Fig. 4 the cylinders are being exhausted to atmosphere and when the pipe 28 and 29 are connected as by the passage 39 the piston 20 is being operated together with the sub-base and mountings.

In Figs. 7 and 8 are shown schematically overhead constructions which illustrate not only the basic operation of present day systems but the operation of my improved invention. The main trolley wires or and at are positive and negative respectively, The trolley frogs a and b are shown as right hand frogs, the branch wires are y and y.

Contacts 0, d and e are arranged as shown in Fig. '7 and connected to operating coils j and f, g and g. It will be noted that when contacts 0 and d are simultaneously engaged by the current collectors h and h the electro-magnets g and y will be energized and the tongues z and a will be moved to guide the current collectors h and h onto the branch Wires y and 11.

When the contacts 0 and e are engaged simultaneously by the current collectors the electro-magnets f and f will be energized and the tongues moved to guide the collectors straight through the frogs on the main wires cc and 0:.

When a trolley bus in moves along parallel to the main wires the collectors are normally aligned transversely at right angles relative to the trolley wires and to the vehicle as shown by bus m in Fig. 8 and when the bus angles as in making a turn the collectors are obliquely aligned relative to the trolley wires as shown by bus 12, the oblique: angle depending upon the angularity of the bus.

The above described system now in general use is found quite satisfactory where the frog is for a turnout of 30 degrees or greater, that is where theangle between the main and branch wires is 30 degrees or greater requiring frogs with corresponding angles between the approach arms.

However where the angle of intersection between the main and branch wires is somewhat less than 30 degrees, the angle which the vehicle makes relative to the main wires in approaching the branch wires to make the turn is not suflicient to provide a suificient longitudinal spacing between the current collectors to engage simultaneously properly placed contacts.

Some intersections require frogs of as low as 23 degrees and in some cases as low as 12 degrees and to insure proper operation of the frog, such frogs are made for power-on and power-off operation requiring the operator to operate his controller to the on or the off position as he passes the intersection of the trolley wires or frog.

However with the invention herein described the vehicle operator in approaching a low angle intersection and Wishing to take the branch angles his bus as normal operation requires and then by manipulating the trolley bases mounted on the bus he is able to increase the longitudinal spacing of the current collectors so they will simultaneously engage the proper contacts.

As before stated there are times when it is most desirable to change the transverse alignment of the current collectors for a right angle alignment to a transverse alignment disposed obliquely to the trolley wires and to the longitudinal axis of the vehicle when the vehicle is traveling par allel to the trolley wires, as for instance when the vehicle operator is about to angle the bus to make a turn traflic may prevent this and the bus may come to stop with the current collectors just in front of the contacts 0 and d but at right angles as bus m in Fig. 8 and when traflic clears sufficiently for the vehicle to proceed it will be too late to properly angle the bus in which case with the invention herein disclosed the vehicle operator may efiect the angling of the current collectors.

Again if the bus has not been able to make a sufficient or proper turn in order for the current collectors to simultaneously engage the proper contacts even when the intersection is 30 degrees or greater then the vehicle operator may correct the condition.

By making the units independently operable the current collectors may be adjusted by the Operator for a right hand or a left hand turn or for straight through movement of the bus.

If desired to substitute .push button operation then the valves 21 and 27' are replaced by the electric operated valves 35 and 35'. Each valve is provided with a casing 36, valve 3'! to alter nately engage seats 38 and 39. The valve is normally closed against seat 38 by spring 50.

The valves 3'! are actuated to open position by the solenoids M which when energized cause the valves 37 to engage the seats 39 which permits fluid pressure to flow from pipe '29 into either pipe 28 depending upon which coil M is energized.

The coils are controlled by push button switches 42 and 42 respectively and which are connected to a source of current on the vehicle. The valves 35 and 35 are normally in their release position as shown in valve 35 in which the fluid pressure from the cylinder l8 escapes to atmosphere through the opening 43 when the push button switches are in their open positions.

When desired to change the transverse alignment of the current collectors relative to the trolley wires the vehicle operator presses either button 42 or 42 depending upon which direction the bus should turn and when the button is released the spring !6 returns the base and current collectors to normal position as shown by m in Fig. 8.

With the above described invention, the bus operator may, if he so desires for any reason, move the vehicle parallel to the trolley wires with the current collectors obliquely aligned relative to the trolley wires, which is not possible with the system now in use in which the bases are fixed.

In Figs. 10, 11 and 12, another embodiment of this invention is shown in which the shifting of the trolley bases and current collectors is accomplished manually.

In Fig. is shown a pair of trolley bases 50 mounted on a sub-base 5! with interposed insulators 52 and the sub-base mounted on a pivotal support 53 which in turn is mounted on the wood members 54 which again are mounted on the roof of vehicle 55.

To guide and stabilize the ends of the sub-base 5|, members 56 are provided and secured to the outer wood members 54.

The trolley bases as in case of Fig. 10 are each provided with a pedestal base 51 upon which is mounted a turret 58 to pivot about a vertical axis. A pole support 59 to receive the trolley pole B6 is pivoted to the turret 58 and the pole held by clamps SI and a spring 62 tends to raise the pole and maintain the current collector (Fig. 9) in contact with the trolley wire. The spring has one end attached to the turret and the other end to the pole support 59 by the adjustable bolt 53.

The pedestal El shown in Fig. 10 is provided with turret, pole support, spring and trolley pole as shown in Fig. 11.

The sub-base 5i, pivots in a horizontal plane on the pin 53 and the guides 56 hold the subbase in place upon the pivotal support 53.

It is evident that when the vertical axes of the bases are in transverse alignment at right angles to the fixed longitudinal axis of the vehicle and the trolley poles are of the same length as shown in Fig. 8 that the current collectors will have the same relation with respect to the vehicle and with the trolley wires when the longitudinal axis of the vehicle parallels the trolley wires.

It is also evident that if one base is moved ahead of the other that their transverse alignment will be oblique to the fixed longitudinal axis of the vehicle and the alignment of the current collectors will be obliquely disposed to the trolley wires when the vehicle axis parallels the trolley wires.

By being able to move the trolley bases as a unit forward or back from a central transverse position (Fig. 10), it is possible to properly cooperate with the contacts of a pair of trolley frogs shown in Fig. 7 to operate the same for a right hand turn, or a left hand turn when left hand frogs are used.

In order to manually manipulate the bases as above described a rod 64 has one end attached to one end of the sub-base 5|. A shaft 65 is positioned within the vehicle and has a lever 65 connecting the shaft to the rod such that when the shaft is turned right or left the rod 64 will be moved right or left and the sub-base and trolley cases also.

To operate the shaft 55, the lower end is associated with a bracket Bl which is mounted at a convenient point within the vehicle and the lower end of the shaft provided with a handle 63 to pivot in a vertical plane where-by the shaft may be moved in either direction. The bracket 61 is provided with three notches to receive the handle and so related to the other parts of the invention that when the handle is in the central notch the trolley bases and current collectors will stand alined at right angles to the longitudinal aXis of the vehicle and when the handle 68 is in either of the other notches the trolley bases and current collectors will be aligned obliquely to thesaid Vehicle axis depending upon the direction the operator wishes to set the trollev from.

The notcheswill hold the handle and sub-base in any one of the three positions desired, the central being the normal position except when it is desired to operate an overhead frog.

If desired to have only the central or normal notch in the bracket 6! then the amount of pivotal movement of the sub-base may be limited by an end of the sub-base engaging a stop such as 59.

It will be evident that a trolley bus equipped as herein disclosed in which the movement of the trolley bases relative to each other and longitudinally of the trolley bus is under control of the bus operator that the vehicle may travel parallel to the trolley wire with the current collectors transversely aligned relative to the trolley wires and to the fixed longitudinal axis of the vehicle suchalignment being either at right angles to or obliquely disposed to the said wires and axis, also the vehicle may take a path obliquely disposed to the trolley wire as when about to make a turn (car N, Fig. 8) and the operator may adjust the relative longitudinal position of the current 001- lectors or in other words their transverse oblique alignment relative to the trolley wire or to the longitudinal axis of the vehicle, especially just prior to the current collector engaging the contacts controlling the trolley frogs.

In the claims the term transverse alignment is broad and coversa right angle or an oblique position of the current collectors or trolley bases relative to the trolley wiresor to the longitudinal axis of the vehicle unless specifically stated; the longitudinal axis of the vehicle is fixed and is not dependent upon the angle the vehicle takes relative to the trolley wires.

Those skilled in the art will, based upon this disclosure, recognize the movement of the bases as possible by substituting a solenoid and plunger for the cylinder and piston in Fig. l and the operation of the unit shown in Fig. 10 by an electric motor of the rotary type.

Modifications to the herein disclosure will be evident to those skilled in the art therefore, I wish to be limited only by my claims.

I claim:

1. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with a current collector to engage a pair of spaced trolley wires as the vehicle moves along its right-of-way, the current collectors adapted to be aligned in transverse relation to the longitudinal axis of the vehicle as it moves along the right-of-way, and means associated with the vehicle and cooperating with the trolley bases and controlled by the vehicle operator to move either base relative to the other base whereby the transverse alignment of the current collectors may be changed relative to the longitudinal axis of the vehicle.

2. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with a current collector to engage a pair of parallel trolley wires as the vehicle moves along its right-of-way, the current collectors arranged in transverse alignment at right angles to the longitudinal axis of the vehicle as it moves along parallel to the trolley wires, and means associated with the vehicle and cooperating with the trolley bases and controlled by the vehicle operator to change the alignment of the current collectors from said right angles to a transverse alignment obliquely disposed to the longitudinal axis of the vehicle.

3. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with means carrying a current collector to engage a pair of parallel trolley wires, the current collectors arranged in transverse alignment at right angles to the longitudinal axis of the vehicle as it moves along parallel to the trolley wires, and means associated with the trolley bases and controlled by the vehicle operator to change the said alignment of the current collectors at will of the operator regardless of the position of the vehicle relative to the trolley wires.

4. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with means carrying a current collector to engage a pair of parallel trolley wires, the current collectors arranged in transverse alignment at right angles to the longitudinal axis of the vehicle as it moves along parallel to the trolley wires, and pneumatic operable means associated with the trolley bases and controlled by the vehicle operator to change the said alignment of the current collectors at will of the operator regardless of the position of the vehicle relation to the trolley wires.

5. In combination with a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with means carrying a current collector to engage a pair of trolley wires, the current collectors normally arranged in transverse alignment at right angles to the longitudinal axis of the vehicle as it moves along parallel to the trolley wires, means associated with the trolley bases to move the trolley bases and means within the vehicle and associated with the second said means to control the operation of the second said means whereby the said alignment of the current collectors relative to the said vehicle axis may be changed to an oblique alignment at Will of the vehicle operator.

6. In combination, a vehicle, a pair of trolley bases each equipped with current collectors to engage a pair of spaced trolley wires, the current collectors normally arranged in transverse alignment at right angles to the longitudinal axis of the vehicle as it moves along parallel to the trolley wires, means under control of the vehicle operator to move one of said trolley bases longitudinally of the vehicle and relative to the other base whereby the transverse alignment of the current collectors will be obliquely disposed to the trolley wires as the vehicle moves along parallel to the trolley wires.

7. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with pivotal means carrying a current collector, the collectors arranged to engage a pair of spaced trolley wires, the current collectors under normal operation aligned in transverse relation at right angles to the longitudinal axis of the vehicle and to the trolley wires, means cooperating with the bases to move them longitudinally of the vehicle relative to each other whereby the aforesaid alignment may be changed to an oblique alignment.

8. In combination, a vehicle, a pair of trolley bases, each base provided with pivotally mounted means carrying a current collector, the collectors arranged to engage a pair of trolley wires, means associated with the bases to move each base 1ongitudinally of the vehicle and of the other base whereby the transverse alignment of the collectors relative to the longitudinal axis of the vehicle may be varied and means operable by the vehicle operator and cooperating with the last said means to control the said movement of the bases at his will.

9. In combination, a vehicle, a pair of trolley bases, each base provided with pivotal means carrying a current collector to engage a pair of trolley wires. means associated with the bases whereby either base may be moved longitudinally of the vehicle and independently of the other base whereby the transverse alignment of the bases and the collectors relative to the longitudinal axis of the vehicle may be varied, means operable by the vehicle operator to control the said movement of the bases and fluid pressure means connected to the second said means to produce a compressed fluid to effect movement of the first said means.

10. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with a pivotally mounted current collector arranged to contact a pair of parallel trolley wires as the vehicle moves along its rightof-way, the position of the collectors relative to each other longitudinally of the trolley wires varying depending upon the angularity of travel of the vehicle relative to the trolley wires and means associated with the bases under control of the vehicle operator to change the said longitudinal position of the current collectors relative to the trolley wires and to each other independently of that cifected by the said position of the vehicle.

11. In a double conductor trolley transit system, a vehicle provided with a pair of trolley bases including a current collector supported by each base, a pair of main conductors and branch conductors and a pair of switches at the intersection of the main and branch conductors and each switch having a guide for guiding the current collectors at the points of intersection, means including contacts positioned for engagement by said current collectors and responsive to engagement therewith for determining the setting of the switches, the engagement of the current collectors with the said contacts to control the setting of the switches being modified by the relative longitudinal spacing of the current collectors as they pass the contacts, the longitudinal spacing of the current collectors along the main conductors varying with the angularity of the Vehicle with respect to the main conductors, means associated with the bases and controlled by the vehicle operator to move the bases longitudinally relative to one another whereby the longitudinal spacing of the current collectors due to the said angularity of the Vehicle may be either increased or decreased independently of the said angularity of the vehicle, at will of the vehicle operator.

12. In a double conductor trolley transit systerm, a vehicle provided with a pair of trolley bases including a current collector supported by each base and operating means associated with the bases and controlled by the vehicle operator to move the bases longitudinally relative to each other, a pair of main conductors and branch conductors and a pair of switches at the intersections of the main and branch conductors and each switch provided with a guide for guiding the current collectors at the points of intersection, means including contacts positioned for engagement with the current collectors and responsive to engagement therewith for determining the setting of the switches, the engagement of the current collectors with the contacts to control the setting of the switches being modified by the relative longitudinal position of the current collectors as they pass the contacts, the longitudinal position of the current collectors depending upon the operation of the operating means by the vehicle operator at his will.

13. In a double conductor trolley transit system, a vehicle provided with a pair of trolley bases including a current collector supported by each base and operating means associated with the bases and controlled by the vehicle operator to move the bases longitudinally of the vehicle, a pair of main conductors and branch conductors and a pair of switches each provided with a movable guide at the intersections of the main and branch conductors, means including contacts positioned for engagement with the current collectors and responsive to engagement therewith for determining the setting of the switches, the engagement of the current collectors with the contacts to control the setting of the switches being modified by the relative longitudinal position of the current collectors as they pass the contacts and the relative longitudinal position of the current collectors depending upon the relative longitudinal position of the trolley bases and the relative longitudinal position of the bases depending upon the operation of the operating means by the vehicle operator.

14. In a double conductor trolley bus system, a pair of main conductors and branch conductors and a pair of switches at the intersection of the main and branch conductors and each switch provided with a guide, means including contacts for determining the setting of the guides, a trolley coach provided with a pair of trolley bases including a current collector pivotally supported by each base and arranged to engage the contacts, the engagement of the current 001- lectors with the contacts to control the setting of the switches being modified by the relative longitudinal position of the trolley bases as the current collectors pass the contacts, means on the vehicle cooperating with the trolley bases and controlled by the vehicle operator to so position the trolley bases that the current collectors will be aligned in transverse relation normal to the longitudinal axis of the coach when desired to direct the current collector straight through the switch and aligned in transverse relation oblique to the said axis when desired to direct the current collector from the main conductors onto the branch conductors. v

15. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with means to support a current collector and arranged to pivot about a vertical aXis independently of each other and to move longitudinally of the vehicle independently of each other and means associated with the vehicle and cooperating with the bases to move said bases longitudinally of the vehicle at will of the vehicle operator whereby the relative longitudinal position of the current collectors may be changed.

16. Mechanism to efiect and control the longitudinal movement of a trolley base mounted on a vehicle comprising, a trolley base, a subbase on which the trolley base is mounted, means to support the sub-base and guide the sub-base as it is moved longitudinally of the vehicle from its normal position, pneumatic operable means associated with the vehicle to move the subbase from its normal position, means connecting the said pneumatic operable means to a source of fiuid pressure including valve means operable by the vehicle operator to control the supply of fluid pressure to operate the said operable means and release the fluid pressure therefrom, yieldable means to return the sub-base to its normal position upon release of the fiuid pressure from the operable means and means to limit the return movement of the sub-base.

17. In combination, a vehicle, a trolley base mounted on the vehicle and provided with a trolley pole supporting a current collector to engage a trolley wire as the vehicle moves along the right-of-way, pneumatic means associated with the vehicle and cooperating with the trolley base to move the trolley base longitudinally of the vehicle from its normal position, means operable by the vehicle operator to control the operation of the pneumatic means and means to prevent accidental movement of the trolley base from its normal position.

18. A combination as set forth in claim 17 in which the means to prevent accidental movement of the trolley base comprises means associated with the trolley base cooperating with means associated with the pneumatic means when the trolley base is in its normal position and one of the cooperating means operable by the pneumatic means to automatically release said cooperation when intentional movement of the trolley base is desired.

19. In combination, a vehicle, a trolley base movably mounted on the vehicle and provided with a trolley pole and a current collector thereon to engage a trolley wire as the vehicle moves along the right-of-way, electrically controlled means associated with the vehicle and cooperatin with the trolley base to move the base longitudinally of the vehicle.

20. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and each base provided with means carrying a current collector, the current collectors to engage a pair of trolley wires, the bases movable relative to each other longitudinally of the vehicle, means associated with the bases to move the bases independently whereby the position of the current collectors longitudinally of the trolley wires relative to one another may be varied and means operable by the vehicle operator to control the operation of the said associated means.

21. In combination, a vehicle, a pair of trolley bases mounted on a sub-base which in turn is mounted on the vehicle to pivot about a vertical axis and each trolley base provided with means pivotally supporting a current collector, the current collectors arranged to engage a pair of spaced trolley wires, the said means mounted to pivot independently of one another and of the sub-base about vertical axes, and operating means associated with the sub-base and controllable by the vehicle operator to move the sub-base on its vertical axis whereby the current collectors will be moved simultaneously and the relative position of the current collectors longitu dinally of trolley wires will be altered.

22. In combination, a vehicle, a pair of spaced trolley bases each provided with means supporting a current collector, the current collectors adapted to engage a pair of trolley Wires, the bases mounted on a sub-base which in turn is mounted on the vehicle to pivot in a horizontal plane on a vertical axis whereby the position of the current collectors relative to one another longitudinally of the trolley wires may be varied between a predetermined minimum and a predetermined maximum and means operable by the vehicle operator to eifect said movement of the sub-base.

23. In combination, a vehicle, a pair of spaced trolley bases each provided with means supporting a current collector, the current collectors adapted to engage a pair of trolley wires, the bases mounted on a sub-base which in turn is mounted on the vehicle to pivot in a horizontal plane on a vertical axis intermediate the trolley bases whereby the position of the current collectors relative to one another longitudinally of the trolley wires be varied, manually operable means within the vehicle and means associated with said subbase and with the said manually operable means whereby the sub-base may be pivoted on its vertical axis to vary the longitudinal spacing of the current collectors along the trolley wires.

24. In combination, a vehicle, a pair of trolley bases mounted on the vehicle and movable parallel to the longitudinal axis of the vehicle, each base provided with pivotally mounted means to support a current collector, the collectors arranged to engage a pair of trolley Wires as the vehicle moves along its right-of-way, and means associated with the vehicle and cooperating with the trolley bases and controlled by the vehicle operator to change the longitudinal spacing of the trolley bases.

ERNST A. LARSSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 643,501 Holmes et a1 Feb. 13, 1900 2,157,859 Moses May 9, 1939 2,243,945 Drummy June 3, 1941 

